Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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Engine - Coolant Temperature Sensor/Switch: Testing and Inspection

1. Immerse sensor in hot water up to mounting threads, then connect one lead of a suitable ohmmeter to hex nut and the other lead to sensor terminal. Observe ohmmeter.
2. Continuity should exist with water temperature between 180-190°F, and should not exist below stated temperatures.
3. Replace thermosensor if other than specified results are obtained.